package com.example.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.example.reggie.common.BaseContext;
import com.example.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器
    public static final AntPathMatcher PATH_MATCHER=new AntPathMatcher();

    /**
     * 1. 获取本次请求的URI
     * 2. 判断本次请求, 是否需要登录, 才可以访问
     * 3. 如果不需要，则直接放行
     * 4. 判断登录状态，如果已登录，则直接放行
     * 5. 如果未登录, 则返回未登录结果
     * @param servletRequest
     * @param servletResponse
     * @param filterChain
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=(HttpServletRequest)servletRequest;
        HttpServletResponse response=(HttpServletResponse) servletResponse;
        //1. 获取本次请求的URI
        String requestURI=request.getRequestURI();
        log.info("拦截到请求：{}",requestURI);
        //2. 判断本次请求, 是否需要登录, 才可以访问
        //不需要进行过滤的请求uri
        String[] urls=new String[]{"/employee/login","/employee/logout","/backend/**","/front/**","/user/login","/user/sendMsg"};
        boolean check=check(requestURI,urls);
        //3. 如果不需要，则直接放行
        if (check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }
        //4. 判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employeeId")!=null||request.getSession().getAttribute("user")!=null){
            if (null==request.getSession().getAttribute("user")) {
                log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("employeeId"));
            }else {
                log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("user"));
            }
            //ThreadLocal增加数据id
            log.info("当前线程:{}",Thread.currentThread().getId());
            BaseContext.setCurrentId((Long) request.getSession().getAttribute("employeeId"));
            if (BaseContext.getCurrentId()==null){
                BaseContext.setCurrentId((Long) request.getSession().getAttribute("user"));
            }
            filterChain.doFilter(request,response);
            return;
        }
        log.info("用户未登录");
        //5. 如果未登录, 则返回未登录结果,通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
    }

    /**
     * 判断传入的reqestURI是否需要进行拦截
     * @param requestURI
     * @param urls
     * @return
     */
    public boolean check(String requestURI,String[] urls){
        for(String url:urls){
            boolean match=PATH_MATCHER.match(url,requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
